Washington -LRB- CNN -RRB- -- The new Army chief of staff , Gen. Ray Odierno , says there would be risks in leaving a large force of U.S. troops in Iraq beyond the present withdrawal deadline of the end of the year .

Odierno , who has served as commander of multinational forces in Iraq , said a large American force could provoke new claims of U.S. occupation and distract from important efforts to develop the Iraqi military 's abilities .

`` I always felt we had to be careful about leaving too many people in Iraq , '' Odierno said Thursday in a question-and-answer session with journalists at the Pentagon .

He would not comment directly on reports that the Obama administration has decided on leaving 3,000 to 5,000 troops , should Iraq make a formal request for them .

`` What I would say is there comes a time , and I 've said it before , when it becomes counterproductive , '' he said . `` So we 've got to decide what that right number is . ''

The general , who served more than four years in Iraq in a variety of roles , said the United States is leaving equipment in Iraq , and transition and training on that equipment , as well as other training for Iraqi troops , has not been completed .

`` We need to probably be there to assist them at certain levels for a while , '' Odierno said .

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Gen. Ray Odierno wants to avoid accusations of U.S. occupation

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Leaving troops also could distract from the effort to boost the Iraqi military , he says

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`` We 've got to decide what that right number is , '' he says